Redlinenz - if yours has the higher dropouts, and the teardrop cutout on the forks, then it's probably 82ish. If you take a look at the Cub, it's got the teardrop fork and repositioned dropouts. This was the year they went to the "Prism" decal with the model name on it on the seat tube, but still made in the original factory in Bunnythorpe (up to a few years ago you could still drive past and make out the Factory Test Track out the front).
I found the Cranks in a shop up north, Andy. The only NOS parts in the build were the cranks, chain, brake cable and tyres. Everything else was as found, but cleaned and restored. I wish I had taken a picture of it before I started.
You could also get the MX1002 with Tuff Wheels; I don't think they made a coaster version of the mags. There was also the Stud, and the top of the line team issue Racing Stud, with all alloy parts. The 24" Assassin came later.